SLOW DOWN light when cold — 2002 360 — Cat ECU’s ?

Hi All — my 2002 360 even when cold is showing the “SLOW DOWN” light. It either stays on and there is a loss of power, or it flashes intermittently. Dealer saying $ 5,200 to replace both cat ECU’s and both thermocouples (temp probes), which seems very high. On YouTube they are installing new ECU’s in about five minutes, but the thermocouples look more difficult. The ECU’s are notorious for failing, so maybe best to have just those done? Or do them myself? thanks

 

Seems odd that they are wanting to change both thermocouples and both thermocouple ECUs. It also sounds like they are wanting to use OEM ECUs.

Did they scan for faults? I doubt both ECUs would fail at the same time. Do you have a basic scanner?

Technistrada may have a cheaper solution on the ECUs and it's DIY.

https://technistrada.com/catalytic-temperature-control-station---355-360-456-550-575

 

This might be voltage related - if so, it can be fixed by charging or replacing the battery.

I personally would not spend 5k for replacing approximately 1k of parts, without having a clear diagnosis first.

 

Spend the $1K and change them yourself. Although, I would clear the error code and confirm if they come back, and on which side.

 

If you have a half hour, a 3 digit IQ, a Dollar General socket set, an internet connection, a 15 pack of Keystone, and working hands, you can do it yourself for literally 15% of what the dealer tried to scr...I mean quoted you for.